Shrinkproofing textiles with polyepoxides, polyamides, and ammonia



SHRINKPROOFING TEXTILES WITH PQLY- EPOXIDEEi, PQLYANHDES, AND AMMQNIA Thompson 3. (Ice, Albany, (Ialifi, assignor to the United States of America as represented by the Secretary of Agriculture No Drawing. Application May 12, 1953 Serial No. 734,800

4 Claims. (Cl. 8-428) (Granted under Title 35, US. Code (1952), see. are

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purpose, is hereby granted to the Government of the United States of America.

This invention relates to and has among its objects the provision of novel processes for shrinkproofing and feltproofing textiles. The invention also includes the provision of improved textiles having superior qualities as to resistance to shrinking and felting. Further objects and advantages of the invention will be evident from the following description.

It is well known in the art that many textile fibers exhibit poor dimensional stability. For example, laundering causes severe shrinkage of woolen textiles. This technical disadvantage seriously restricts the applications of wool in the textile industry and much research has been undertaken in order to modify the natural fiber in order to improve its shrinkage properties. In general, known methods of treating wool to improve its shrinkage characteristics have the disadvantage that the hand of the fabric is impaired, or, if the amount of agent applied is limited to avoid impairment of hand, the degree of shrinkage protection is relatively poor.

In accordance with the invention, wool, or other textile material, is impregnated with a polyepoxide and a polyamide, then cured by subjection to ammonia in the vapor state. This procedure yields a product which is virtually shrinkproof under normal laundering procedures while the hand, resiliency, porosity, tensile strength, color and other valauble properties of the textile are retained. Additionally the treated textile exhibits a great improvement in resistance to creasing and wrinkling as compared to the original textile.

The prior art discloses methods for shrinkproofing textiles by applying polyepoxides and curing the polyepoxide with such agents as triethylamine,ethylene diamine, diethylene triamine and other amino compounds. The process of the inventions afiords many advantages over the known procedure, as follows:

(a) In the process of the invention the original color of the textile is retained. For example, white wool treated in accordance with the invention retains its white color. In the known process the treated wool develops yellowness. Dyed woolen textiles treated in accordance with the invention retain their original colors in undiminished brightness whereas the processes of the prior art cause a graying or dulling of the fabrics.

(b) The process of the invention yields products of especially soft and resilient properties and more shrinkproofing efiect is attained per unit weight of resinous material deposited in the fibers.

(c) The curing treatment of the inventioninvolving contacting the polyepoxide and polyamide-impregnated textile with ammonia in the vapor phase-has the advantage that this curing agent can penetrate readily into the textile and ensure complete and uniform cure of the tates t 2,933,366 Patented Apr. 19, 1960 polyepoxide-polyamide composition. Moreover, the ammonia treatment does not disturb the appearance, dimensions, or construction of the textile. There is no change in nap, no wrinkling. Textiles having pleats, folds, etc. retain such forms without change. Also, since the curing involves a vapor phase rather than the usual liquid treatment, no wringing or other mechanical treatments are required. This means that no wrinkling or other change in the construction or arrangement of the textile is involved.

In applying the process of the invention in practice, the textile is first impregnated with a liquid preparation containing the polyepoxide and polyamide. The impregnation is performed in any of the usual ways. For example, the polyepoxide-polyamide composition is applied by spraying, brushing, dipping, etc. To assist in wetting the textile, it may be run through padding rolls or the like. Excess liquid may be removed by passing the textile through wringer rolls. The proportion of active material in the liquid preparation is usually so selected that there is deposited on the textile about /2 to 10% of its weight of the mixture of the pol'yepoxide and polyamide. In general, the greater the proportion of these agents, the greater will be the shrinkage protection afforded. The relative proportions of polyamide and polyepoxide may be varied. Usually there is employed about from 0.1 to 5 parts by weight of polyamide per part by weight of polyepoxide. After the textile has been impregnated with the polyepoxidepolyamide preparation it is cured directly or dried in air prior to curing, the latter procedure being generally preferred.

Curing of the polyepoxide and polyamide impregnated textile involves subjecting it to the vapors of ammonia. This may conveniently be done by hanging the textile in a chamber in which is exposed an open vessel containing ammonium hydroxide. In the alternative, ammonia gas from a tank may be bled into the chamber. No special precautions need be taken as to addition or elimination of moisture from the system. The textile is allowed to remain in contact with the ammonia vapors until the polyepoxide-polyamide composition is cured that is, until it is rendered insoluble so that it is not removable from the textile by laundering. The temperature of the ammonia vapor may be at room temperature or may be increased to about 150 C. to obtain faster cure. At room temperature the cure is complete in about 12 to 24 hours; at C. it is complete in about a halfhour. No effort is made to control the amount of ammonia other than to ensure that the chamber at all times contains free ammonia so that an excess of ammonia is always available for reaction with the polyepoxidepolyamide composition.

The polyepoxides used in accordance with the invention are organic compounds having at least two epoxy groups per molecule and may be saturated or unsaturated, aliphatic, cycloaliphatic, aromatic or heterocyclic and may be substituted with non-interfering substituents such as hydroxyl groups, ether radicals, and the like. Polyepoxides containing ether groups, generally designated as polyepoxide polyethers, may be prepared as well known in the art by reacting a polyol with a halogencontaining epoxide employing at least 2 moles of the halogen-containing epoxide per mole of polyol. Thus, for example, epichlorhydrin may be reacted with a polyhydric phenol in an alkaline medium. In another technique the halogen-containing epoxide is reacted with a polyhydric alcohol in the presence of an acid-acting catalyst such as hydrofluoric acid or boron trifluoride and the product is then reacted with an alkaline compound to effect a dehydrohalogenation. A preferred example of the halogen-containing epoxide is epichlorhydrin; others are epibromhydrin, epiodohydrin, 3-chlo ro-1,2-ep0xyassesses butane, 3-bromo-l,2-epoxyhexane, and 3-chloro-l,2- epoxyoctane. Examples of polyols which may be remethyl resorcinol, 2,2-bis(parahydroxyphenyl) propane,

2,2-bis(parahydroxyphenyl)butane, 4,4-dihydroxybenzophenone, bis(parahydroxyphenyl)ethane, 1,5-dihydroxynaphthalene, 1,4-dihydroxycyclohexane, bis (2,2'-dihydroxydinaphthyl) methane, etc. Illustrative examples of pol-yepoxide' polyethers are as follows:

1-,4'bis(2,3-epoxypropoxy)benzene; l,3-bis(2,3-epoxypropoxy) benzene; 4,4-bis (2,3-epoxypropoxy) diphenyl ether; l-,8-bis(2,3-epoxypropoxy) octane; l,4-bis(2,3-epoxypropoxy )cyclohexane; 4,4'-bis (2-hydroxy-3,4-epoxybutoxy) diphenyl dirnethylmethane; l,3-bis(4,5-epoxypentoxy)-5-chlorobenzene; 1,4-bis(3,4-epoxybutoxy)-2-chlorohexane; diglycidyl thioether; diglycidyl ether; ethlyene glycol diglycidyl ether; propylene glycol diglycidyl ether; diethylene glycol diglycidyl ether; resorcinol diglycidyl ether; l,2,3,4-tetrakis(2*hydroxy-3,4-epoxybutoxy)butane; 2,2-bi's(2,3-epoxypropoxyphenyl)propane; glycerol triglycidyl ether; mannitol tetraglycidyl ether; pentaerythritol tetraglycidyl ether; sorbitol tetraglycidyl ether; etc. It is evident that the polyepoxide polyethers may or may not contain hydroxy groups, depending primarily on the proportions of halogen-containing epoxide and polyol employed. Polyepoxide polyethers containing polyhydroxyl groups may also be prepared by reacting, in known manner, a polyhydric alcohol or polyhydric phenol with a polyepoxide in an alkaline medium. Illustrative examples are the reaction product of glycerol and diglycidyl ether, the reaction product of sorbitol and bis(2,3-epoxy-2-methylpropyl)ether, the reaction product of pentaerythritol and 1,2,4,5-diepoxy pentane, the re action product of 2,2-bis(parahydroxyphenyl)propane and bis(2,3-epoxy-2. methylpropyl)ether, the reaction product of resorcinol and diglycidyl ether, the reaction product of catechol and diglycidyl ether, and the reaction product of 1,4-dihydroxycyclo-hexane and diglycidyl ether. A particularly preferred type of polyepoxide polyether is that prepared by reacting epichlorhydrin with 2,2 bis(parahydroxyphenyl) propane. ,The structure of these compounds is illustrated by the formulaamino butane, 1,3-diaminobutane, hexamethylene diamine, 3-(N-isopropylamino)proplyamine, 3,3'-imino -bispropylamine, and the like. Typical polycarboxylic acids which may be condensed with the polyamines to form polyamides are glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, isophthalic acid, terephthalic acid, beta-methyl adipic acid, 1,2-cyclohexane dicarboxylic acid, malonic acid and the like. Depending on the amine and acid constituents and the conditions of condensation, the polyamides may have molecular Weights varying about from 1,000 to 10,000 and melting points about from 20-200 C. Particularly preferred for the purpose of the invention are the polyamides derived from aliphatic polyamines and polymeric fat acids. Such products are disclosed for example by Cowan et al., Patent No. 2,450,940. Typical of these polyamides are those made by condensing ethylene diamine or diethylene triamine with polymeric fat acids produced from the polymerization of drying or semi-drying oils, or the free acids, or simple aliphatic alcohol esters of such acids. The polymeric fat acids may typically be derived from such oils as soybean, linseed, tung, perilla, oiticica, cottonseed, corn, tall, sunflower, safllower, and the like. As well known in the art, the fat acids combine to produce a mixture of dibasic and higher polymeric acids. Usually the mixture contains a preponderant proportion of dimeric acids with lesser amounts of trimeric and higher polymeric acids, and some residual monomeric acid. A typical polyamide of this type is, for example, one produced by heating soybean dimeric fatty acids and diethylene triamine. V

A primary advantage of employing a polyamide in conjunction with the polyepoxide is that the former enhances curing of the polyepoxide by reaction therewith producing especially desirable resinous compositions which are characterized by outstanding ability to provide shrinkproofing and which are especially permanent in that they are not removed from the fabric by repeated laundering.

The polyepoxide and polyamide are preferably applied to the textile material in theform of a solution. or dispersion to ensure uniform impregnation of the fibrous elements. Aqueous solutions may be used, for example, where the selected polyepoxide and polyamide are soluble in this medium. In many cases other volatile solvents may be required such as acetone, benzene, alcohol, ethylene glycol, monomethyl ether, ethylene glycol monoethyl ether, dioxane, etc., depending on the property of the agent in question. It is often preferred to apply the agents in the form of aqueous emulsions prepared wherein n varies between zero and about 10, correspond ing to a molecular weight about from 350 to 8,000.

Polyepoxides which. do not contain ether groups may be employed as for example 1,2,5,6-diepoxyhexane; butadiene dioxide, that, is, 1.,2,3,4-diepoxybutane, isoprene dioxide; limonene dioxide.

The. polyamides used in accordance with the invention are those derived from lower aliphatic polyamines and polybasic acids. Methods. of preparing these polyamides by condensation of polyamines and polycarboxylic acids are Well known in the art and need not be described here. One may prepare polyamides containing free amino groups or tree carboxylic acid groups or both free amino and free carboxylic acid groups. Generally it is preferred to employ polyamides which contain free amino groups since the active hydrogens on these groups are especially reactive with the epoxy groups of the polyepoxide to form insoluble polyepoxide-polyamide reaction products. The polyamides may be derived from such polyamines as ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, 1,4-diby application of any of the known emulsification techniques. A preferred procedure is to dissolve the polyepoxide and'polyamide in a suitable quantity of alcohol or other volatile organic solvent and add thissolution to water with vigorous agitation. In this way contact of the solution with Water will precipitate the polyepoxide and polyamide in, minute'particles which will be relatively easy to eniulsify. To assist in forming and maintaining the emulsion one may add a small proportion of a conventional emulsification agent. For this purpose one may employ agents such as soaps, long-chain alkyl sulphates, long-chain alkyl benzene sulphonates, alkyl esters of sulphosuccinic acid, etc., typical examples being sodium lauryl sulphate, sodium alkyl c c benzene sulphonate, sodium dioctylsulphosuccinate, etc.' Preferably, emulsifying agents of the nonionic type are employed, for example, sorbitan laurate, polyoxyethylene ether of sorbitan laurate, polyoxyethylene ether of scrbitan monostearate, polyoxyethylene ether of sorbitan distearate, sorbitan trioleate, iso-octyl phenyl ether of polyethylene glycol, and so forth. Other suspending agents as gums, gelatin, pectin, soluble starch, dextrins, etc. can be used to keep the polyamide and polyepoxide in suspension. It is obvious that the proportion of active materials in the solution or dispersion may be varied as necessary to deposit on the textile material the desired percentage of polyepoxide and polyamide. Usually it is preferred to apply to the textile a single solution or dis persion containing both polyepoxide and polyamide. If desired, however, these agents may be serially applied, in any sequence, in separate solutions or dispersions.

The process of the invention is particularly adapted to the treatment of wool but is also advantageously applicable to other textiles including mohair; animal hair; silk; fibers made from proteins such as zein, casein, peanut protein, soybean protein, keratins, ete.; cotton; regenerated cellulose; vicose; linen; cellulose; acetate; etc. The textile material may be in the form of fibers, threads, yarns, woven or knitted fabrics, garments, etc.

The invention is further demonstrated by the following illustrative examples.

Example 1 Pieces of white woolen cloth were padded with emulsions of a polyepoxide and polyamide. in these emulsions, the total concentration of these agents was varied (as set forth below) but the relative proportion of the two agents was maintained constant at 0.67 part of polyamide per part of polyepoxide. In each case 2% of isooctylphenyl ether of polyethylene glycol (Triton-X400) was used as the emulsifying agent. The polyepoxide was a. commercial product consisting essentially of 2,2-bis (2,3-epoxypropoxyphenyl) propane prepared by reacting epichlorhydrin with 2,2-bis(parahydroxyphenyl) propane. The polyamide was a commercial product being a condensation product of diethylene triamine and heat-dimerized unsaturated fat acids. It was a viscous liquid at ordinary temperatures with a viscosity of A A on the Gardner- Holt scale at 25 C. and a specific gravity of 0.99 at 25 C.

The impregnated cloth samples were then placed in a chamber where they were exposed to ammonia vapors for 72 hours at room temperature. It was observed that all the cured samples were white in color.

The treated samples of cloth and a sample of untreated cloth (control) were subjected to tests to determine their shrinkage characteristics. In these tests the cloth samples were subjected to a laundering operation wherein the cloth was violently agitated in an Accelerator for 3 min. in a 0.5% solution of sodium oleate at 40 C. with a cloth to solution ratio of 1 to 35. The area of the cloth was measured before and after laundering. The washing tests were carried out in duplicate. The results are tabulated below, the shrinkage values being averages of the duplicate tests.

Samples of white woolen cloth were padded with emulsions of polyepoxide and polyamide in a total concentration of 5% but at various relative proportions as set forth below. The same emulsifier as in Example 1 was employed. The polyepoxide and polyamide were also as described in Example I. The impregnated cloths were cured by exposure to ammonia vapors for 72 hrs. at 25 C. It was observed that all the cured samples were Pickup of cured Area Parts of polypolyepoxideshrinkage Sample amide per part polyamide by after of poiyepoxide cloth, percent laundering,

percent 1 Minus sign indicates cloth expanded in area.

Example III An emulsion was prepared containing 1% polyepoxide A, 4% polyepoxide B and 5% polyamide. Five percent of iso-octylphenyl ether of polyethylene glycol (Triton- X-) was used as the emulsifying agent. Polyepoxide A was a commercial product consisting essentially of 2,2-bis(2,3-epoxypropoxyphenyl) propane. Polyepoxide B was a commercial preparation being the reaction prodnot of epichlorhydrin and glycerol and containing on the average of a little more than 2 epoxy groups per mol of glycerol. This material is a liquid at ordinary temperatures, has a viscosity of 0.9 to 1.5 poises at 25 C., and has an epoxide equivalent of -165. The polyamide was as described in Example I.

The above emulsion was padded onto pieces of white woolen cloth. The impregnated cloth was then exposed to ammonia vapors at room temperature for 72 hours. The pickup of cured polyamide-polyepoxide on the cloth was 5.5%. The cured cloth was white in color. Shrinkage tests were carried out as described above. Area shrinkage of the treated cloth was zero as compared with 50% area shrinkage for a control (untreated) piece of the same cloth.

Example IV Pieces of white woolen cloth were padded with aqueous emulsions of a polyepoxide and polyamide. In these emulsions the total concentration of these agents was varied (as set forth below) but the relative proportion of the two agents was maintained constant at 0.67 part polyamide per part polyepoxide. The emulsions were prepared with the same emulsification agent as described in Example I. The polyamide was the same as described in Example I. The polyepoxide was a commercial product consisting essentially of 2,2-bis(2,3-epoxypropoxyphenyl)propane.

The impregnated cloth samples were exposed to ammonia vapors for 22 hours at room temperature. It was observed that the cured cloth samples were white in color. Shrinkage tests were conducted as described above. The results are tabulated below-- Total cone. of Pickup of cured Area polyamide and polyamide shrinkage Sample polyepoxide in polyepoxide by after emulsion, cloth, after percent percent laundering percent 2 3. 3 0 1 3. 6 0 3 0. 5 2. 9 0 control. 50

carboxyl groups, the total amount of polyepoxide and polyamide deposited on the textile being about from 0.5 to 10% of the weight of the textile, the proportion of polyamide being about from 0.1 to 5 parts by Weight per part by weight of polyepoxide, and exposing the impregnated textile to ammonia in the vapor phase to cure and insolubilize the polyepoxide and polyarnide on the textile fibers.

2. The method of shrinkproofing wool without significant impairment of its hand which comprises impregnating wool with (A) a. polyepoxide containing at least two epoxy groups per molecule and being free from functional groups other than hydroxyl groups, ether groups, and epoxy groups and (B) a polyamide of a lower aliphatic polyamine and a polymeric fat acid containing at least two carboxyl groups, said polyamine having free amine groups, the total amount of polyepoxide and polyamide deposited on the wool being about from 0.5 to 10% of the weight of the wool, the proportionof polyamide being about from 0.1 to 5 parts by weight per part by weight of polyepoxide, and exposing the impregnated W001 to ammonia in the vapor phase to cure and insolubilize the polyepoxide and polyamide on the Wool fibers.

3. The process of claim 2 wherein the polyepoxide is a polyglycidyl ether of glycerol.

4. The process of claim 2 wherein the polyepoxide is a polyglycidyl ether of 2,2-bis(parahydroxyphenyDpropane.

References Cited in the file of this patent UNTTED STATES PATENTS 

2. THE METHOD OF SHRINKPROOFING WOOL WITHOUT SIGNIFICANT IMPAIRMENT OF ITS HAND WHICH COMPRISES IMPREGNATING WOOL WITH (A) A POLYEXPOXIDE CONTAINING AT LEAST TWO EPOXY GROUPS PER MOLECULE AND BEING FREE FROM FUNCTIONAL GROUPS OTHER THAN HYDROXYL GROUPS, ETHER GROUPS, AND EPOXY GROUPS AND (B) A POLYAMIDE OF A LOWER ALIPHATIC POLYAMINE AND A POLYMERIC FAT ACID CONTAINING AT LEAST TWO CARBOXYL GROUPS, SAID POLYAMINE HAVING FREE AMINE GROUPS, THE TOTAL AMOUNT OF POLYEPOXIDE AND POLYAMIDE DEPOSITED ON THE WOOL BEING ABOUT FROM 0.5 TO 10% OF THE WEIGHT OF THE WOOL, THE PROPORTION OF POLYAMIDE BEING ABOUT FROM 0.1 TO 5 PARTS BY WEIGHT PER PART BY WEIGHT OF POLYEPOXIDE, AND EXPOSING THE IM PREGNATED WOOL TO AMMONIA IN THE VAPOR PHASE TO CURE AND INSOLUBILIZE THE POLYEPOXIDE AND POLYAMIDE ON THE WOOL FIBERS. 